The use of self-closing discharge nozzles on packages for dispensing fluid materials is generally known in the art. For example, U.S. Pat. No. 2,071,657 issued to Richardson on Feb. 23, 1937 discloses a collapsible tube employing a self-closing nozzle employing a pair of self-closing jaws. The jaws, which are open to form an orifice in response to pressure of the fluid material, close off the discharge end of the tube when the pressure of the fluid material inside the container is relieved.
Another exemplary structure of this type is shown in U.S. Pat. No. 3,506,163 issued to Rauh et al. on Apr. 14, 1970. The patent to Rauh et al. discloses a collapsible container for a flowable material. The container includes a normally closed spout which opens automatically in response to a pressure increase inside the container. At the end of any given product dispensing cycle the spout automatically assumes its closed position, thus maintaining the flowable material within the container out of contact with the atmosphere as well as preventing the container from expanding back to its initial volume. The container of Rauh et al. is progressively collapsed as the flowable material is dispensed.
Packages with self-sealing fitments which eliminate the need for a conventional closure intermediate dispensing cycles are also generally known in the art. For example, U.S. Pat. No. 2,175,052 issued to Bull et al. on Oct. 3, 1939 discloses a dispensing closure for attachment to containers for materials such as toothpaste, shaving cream, etc. to which internal pressure is applied to discharge the contents therefrom.
Another prior art container closure of the self-sealing variety is disclosed in U.S. Pat. No. 1,825,553 issued to Smith on Sept. 29, 1931. Smith discloses a collapsible tube which is preferably soft and flexible and may serve as a receptacle for dentifrice, shaving cream, paste or other viscous substances. To extrude contents from the tube Smith discloses that it is only necessary, after the cap has been removed, to apply pressure to the tube and this pressure will force the contents of the tube against the top of the cavity of the closure and cause the valve slit to open and allow the tube contents to pass out as shown in FIG. 3. When the pressure on the tube is released, the elasticity of the closure member allegedly forces the slit tightly closed and prevents any further extrusion of the contents.
A greatly improved self-sealing fluid or fluidized material dispensing package is disclosed in commonly assigned British Patent Application No. 2,158,049A published on Nov. 6, 1985 in the names of James Lee Drobish and Leo Edward Taske and entitled SELF-SEALING DISPENSING VALVE, said commonly assigned British Patent Application being hereby incorporated herein by reference. The aforementioned commonly assigned British Patent Application discloses a resiliently deformable container having at least one discharge orifice. The orifice includes a resiliently deformable diaphragm valve having a portion exhibiting a generally concave shape. The valve is sealingly secured to the container across its orifice. The diaphragm valve is oriented so that it is normally inwardly concave in relation to the container. The concave shaped portion of the diaphragm valve includes at least one slit, preferably passing through the center of the discharge orifice of the container in a substantially straight line. The discharge orifice preferably comprises a container neck and the concave shaped portion of the diaphragm valve is preferably comprised of a resilient material with a low flexural modulus, such as silicone rubber, polyvinyl chloride, urethane, ethylene vinyl acetate, styrene butadiene copolymer or the like. The resiliently deformable container is preferably comprised of a resilient material with a somewhat higher flexural modulus such as polyethylene, polypropylene, polyvinylchloride, polyethylene terepthalate or the like.
In a particularly preferred disclosed embodiment of the Drobish and Taske package a snap-on auxiliary sealing member having a size and shape which substantially coincides with the outermost surface of the concave shaped portion of the valve is employed in an attempt to prevent actuation or opening of the concave shaped portion of the valve until the storage and dispensing package has been delivered to an placed in service by the consumer. In an alternative embodiment, the diaphragm valve is provided to the consumer without a slit, and the consumer is given directions on how to provide the slit by means of a knife or razor blade. In still another embodiment, a line of weakening is provided in the diaphragm valve such that upon the application of manual force to the valve by the consumer, the line of weakening ruptures to form a slit in the concave shaped portion of the valve.
Although storage and dispensing packages of the type disclosed in the aforementioned commonly assigned British Patent Application of Drobish and Taske have performed admirably well once they reach the consumer, some difficulties have been experienced on package embodiments using the pre-cut valves. In particular, unwanted discharge of product has been observed when the packages are subjected to sudden impact loads and/or compressive loads during transit, such as when a case of product is dropped or when it is subjected to a clamping operation in a warehousing or shipping operation. The impact and/or compressive loads experienced in transit or handling are often sufficient to cause the pre-cut valves to undergo momentary inversion, thereby dislodging the auxiliary sealing member and discharging a quantity of product through the valve. This causes damage and mess to the package and shipping case prior to its even reaching the retailer, let alone the end user. Such unintentional discharge or product from one package may also contaminate a number of the surrounding packages in the same or even adjacent shipping cases, thereby aggravating the severity of the loss.
While it is believed that such premature discharge of product can in most instances be avoided by shipping the package without precutting the slit or slits in the concave portion of the valve, this means that the consumer must either cut the concave shaped portion to create the slit or rupture the concave shaped portion along a predetermined line of weakening. These approaches are not only inconvenient to the consumer, but if the valve cutting or rupturing operation is not properly performed, it can destroy the highly desirable operating characteristics of the valve.